In a case where ink is stored for a long period of time in an ink container, in a case where due to the low frequency of use of a printing device, the ink in the ink container mounted on the printing device is not consumed for a long period of time, and in other cases, the ink used in the printing device may sometimes change with time in the ink container.
For example, (a) in the case of pigment ink, coarse-grained ink is generated due to the condensation of a pigment, and this coarse-grained ink precipitates in the ink container. (b) Also, there is a case where foreign matter which has mixed during the manufacturing of ink precipitates in the ink container. (c) Furthermore, there is also a case where in some combinations of ink and the material for the ink container, added components of the material precipitate are deposited and precipitate in the ink container.
This kind of ink containers which store the ink used in a printing device, are disclosed, for example, in Japanese Patent Laid-Open No. 4-214361, Japanese Patent Laid-Open No. 2001-199455 and Japanese Patent Laid-Open No. 6-211273.
An ink container described in Japanese Patent Laid-Open No. 4-214361 is provided with an ink bag formed from a flexible film etc. as an ink container body which stores ink, and its construction is such that this ink bag is supported by being sandwiched between a top plate and a bottom plate. However, this ink bag is of such a simple construction that the ink bag contracts and is deformed as ink is consumed and the top and bottom plates of the ink bag only suppress the dancing of the ink bag. Therefore, precipitates of coarse-grained ink etc. standing on the bottom of the ink bag flow out of the ink bag due to the contraction and deformation and are supplied to the printing device, and it is difficult to make coarse-grained ink etc. remain in the ink bag.
An ink container described in Japanese Patent Laid-Open No. 2001-199455 is provided with an ink bag body formed from a flexible film etc., and its construction is such that a supporting member is provided in this ink container body. However, this supporting member only reinforces the ink container body and only prevents the deformation of the ink container body which might be caused by taking the content (ink) out of the ink container body. The supporting member does not adopt such a construction that an arbitrary amount of coarse-grained ink etc. is intentionally left in the ink container body.
An ink container described in Japanese Patent Laid-Open No. 6-211273 has an inner bag formed from a flexible film etc. as an ink container body which stores ink, and its construction is such that the outer surface of this inner bag is stuck to the inner surface of an outer box formed from carton. However, the outer box only constrains part of the inner bag. Like the supporting member of Japanese Patent Laid-Open No. 2001-199455 above, also this outer box does not adopt such a construction that an arbitrary amount of coarse-grained ink etc. is intentionally left in the ink container body.
If precipitates of coarse-grained ink etc. as described above flow out of the ink container to the printing device and supplied to the device, the following troubles occur.
In a case where the printing device is an IJ printer (“IJ” means ink jet; IJ will be hereinafter used as ink jet), during the passage of coarse-grained ink through fine pores of an IJ head, the coarse-grained ink impedes the formation of an ink meniscus in the IJ head and appropriate ink discharge is impossible. In some cases, the pores of the IJ head become clogged with the coarse-grained ink, thereby causing the trouble that an appropriate print image cannot be obtained. In the worst case, fine pores of the IJ printer become clogged with the coarse-grained ink and the IJ printer itself does not work normally and is brought into an unusable condition.
In a case where the printing device is a stencil printing device, when coarse-grained ink passes through pores of an ink-passing body of a printing cylinder, such as a plate cylinder and a screen, the pores are clogged with the coarse-grained ink, thereby causing the trouble that an appropriate print image cannot be obtained. In the worst case, fine pores of the stencil printing device become clogged with the coarse-grained ink and the stencil printing device itself does not work normally and is brought into an unusable condition. This applies also to a screen printer, a stamp containing ink in a fine porous section, etc.
Patent Document 1: Japanese Patent Laid-Open No. 4-214361
Patent Document 2: Japanese Patent Laid-Open No. 2001-199455
Patent Document 3: Japanese Patent Laid-Open No. 6-211273